Testing is a hugely interesting topic for some, mainly developers, looking to develop some intuition about how a particular piece of software works to integrate into their use case. It is very helpful, therefore, that Bitcoin provides access to a ‘Testnet’ for the transmission and spending of transactions in a sandbox where Bitcoin Testcoins have no real value.
As this is hugely beneficial for normal Bitcoin developers, we at Mastercoin also realized the huge benefit for the developer community if we were able to send TestNet transactions in Mastercoin, which would reduce the cost to develop on our infrastructure.
Without further ado:
A guide to running TestNet for Mastercoin (A primer):
- Download and build the latest hash/tag of MasterCore from Github here.
- Run MasterCore in Testnet from the command-line, `./bitcoind -txindex -testnet`and allow it to sync to the furthest block (at time of writing, this is 262068). Command line output might result 
- Check if you have any Bitcoin Testnet addresses with ‘./bitcoind listaccounts’and then ‘./bitcoind getaccountaddress’. You can also generate a TestNetaddress using vanitygen (https://github.com/samr7/vanitygen). Testnet addresses start with an ‘m’, usually. Take note of this address.
- Request some Testnet coins from the TestNet Faucet (https://tpfaucet.appspot.com/ – Please do not abuse!)
- Add a file to ~/.bitcoin/testnet3/ called ‘mastercoin_balances.txt’.In this file enter your address, followed by your desired MSC amount, followed by a 0 
You can send some MSC now using the following command (full list of commands are obtained using ‘./bitcoind help’):
`./bitcoind send_MP (your address) (their address) (amount-in-floating-point)`
And that’s the quickstart guide for TestNet. There are numerous other commands suffixed with ‘_MP’ in the output of `bitcoind help`, feel free to test those out. Report bugs and difficulties to the repository directly if you locate any, and questions can be asked of the devs through either Github Issues, the mailing list, or directly through email.
 For example, the file contents would look like:
 Example of successful send on TestNet
 Example of debug output